title: [Isolation and purification of recombinant human lactoferrin (rhLF) from transgenic rice and its antibacterial activities].
abstract: OBJECTIVE
  To study the isolation and purification of recombinant human lactoferrin (rhLF) from transgenic rice, and to check its antibacterial activities.
  
  
  METHODS
  After isolated rhLF from transgenic rice via saturated ammonium sulfate precipitation, then purified it through CM Sepharose FF-exchange chromatography and molecular sieve chromatography Sephadex G25. The inhibition effects under different concentrations of rhLF (0.25, 0.5, 1.0, 2.0, 4.0, and 5.0 mg/ml) against Salmonella typhimurium, Staphyloccocus aureus, Bacillus cereus, Listeria monocytogenes were observed, using broth microdilution method.
  
  
  RESULTS
  The rhLF was obtained at a higher purity (about 90%) through successful isolation and purification. After Coomassie blue staining, Westernblot and mass spectrometer analysis, it was identified as the purpose protein with the molecular weight of approximately 79 kDa. The antibacterial experiments showed that 5 mg/ml and 4 mg/ml rhLF could inhibite Salmonella typhimurium and Staphylococcus aureus persistently, 2 mg/ml and 1 mg/ml rhLF showed a significant inhibitory effects in the later period; while 0.5 mg/ml or lower concentration, showed no inhibitory effects. As to Bacillus cereus, only 5 mg/ml and 4 mg/ml rhLF exhibited certain inhibitory effects within 18 hours. Listeria monocytogenes was inhibited within 18 hours just at 5 mg/ml rhLF.
  
  
  CONCLUSIONS
  The rhLF could be successfully separated and purified from transgenic rice, and the purified protein still has significant antibacterial activities.
authors.affiliation: Institute of Nutrition and Food Safety, Chinese Centre for Disease Control and Prevention, Beijing 100050, China. jhwu2012@163.com
authors.forename: Jinghuan
authors.initials: J
authors.lastname: Wu
authors.forename: Lichen
authors.initials: L
authors.lastname: Yang
authors.forename: Gaige
authors.initials: G
authors.lastname: Liu
authors.forename: Zhaolong
authors.initials: Z
authors.lastname: Gong
authors.forename: Jikai
authors.initials: J
authors.lastname: Liu
authors.forename: Yujie
authors.initials: Y
authors.lastname: Hu
authors.forename: Yunchang
authors.initials: Y
authors.lastname: Guo
authors.forename: Jianhua
authors.initials: J
authors.lastname: Piao
authors.forename: Zhicheng
authors.initials: Z
authors.lastname: Shen
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Yang
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis / Q000302:isolation & purification / Q000494:pharmacology*; D001409:Bacillus cereus / Q000187:drug effects; D006801:Humans; D007781:Lactoferrin / Q000096:biosynthesis / Q000302:isolation & purification* / Q000494:pharmacology; D008089:Listeria monocytogenes / Q000187:drug effects; D012275:Oryza / Q000737:chemistry / Q000235:genetics*; D030821:Plants, Genetically Modified; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification* / Q000494:pharmacology; D012486:Salmonella typhimurium / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D011994:Recombinant Proteins; D007781:Lactoferrin